The documentary Bathtubs Over Broadway suggests that those productions got positive reponses from employees, but that probably had to do with good production values (some of the shows cost more than actual Broadway runs) and it being an expenses-paid day trip for everybody.

That's actually where I learned about industrial musicals myself. I wanted to link a more direct explanation, however.

Remember "The Internship"?

These still exist in the form of corporate newsletters filled with high-production videos of very serious people saying very serious things. It's still considered a musical, it's just you hafta have the right Dadaist frame of mind to get it.